This proposal requests continuing support for an Epidemiology and Biostatistics Research Program as a major component of the Los Angeles County/University of Southern California Cancer Center. A large part of the research effort is the Cancer Surveillance Program (CSP) headed by Dr. Thomas Mack. The CSP provides prompt reporting and detailed demographic data on virtually all new cancer cases diagnosed in the entire population of seven million residents of Los Angeles County. A major function of the CSP is to provide cancer patient identification for etiologic field studies. The descriptive information from the CSP provides additional etiological clues and a system for checking the consistency of suggested causal associations with cancer rates in the population. The CSP also identifies high risk program targets, and constitutes a cancer research organization with a presence in each of the county's diagnostic facilities. The Biostatistics Unit headed by Dr. Malcolm Pike supports some field staff as well as the analytic component of our field studies. Development of new statistical methods to deal with these field studies and other cancer related studies is also undertaken by this unit. Funds for most field studies are currently being obtained from several research contracts and grants. The desirability of having the capability of making a rapid and flexible response to newly suggested hypotheses demands some field staff without unalterable commitments.